Short Summary

It is the morning of an Apollo/Saturn V launch.

The Mobile Service Structure is backed off?

Description

It is the morning of an Apollo/Saturn V launch.

The Mobile Service Structure is backed off to its parking place. The mighty thirty-six story high space vehicle is still linked to its Mobile Launcher which has two main structures: the umbilical tower and the launch platform.

The umbilical tower supports nine service arms which provide access to the launch vehicle. Some of these arms are retracted prior to engine ignition,t eh others at lift-off.

Apollo/Saturn V is also attached to earth - and the launch platform - by three other kinds of mechanists: There are four powerful clamps - the Hold Down Arms... one of them is seen in this picture on the lower left.

There are three tail service meet assemblies, one of which is seen here on the right.

And there are several "soft release" mechanisms.

At T minus 3 minutes 6 seconds, the Launch Director at the Cape gives the firing command which activates the automatic launch sequencer.

At T minus 8.9 seconds the ignition sequence begins, as shown here in slow motion. (At T minus 50 seconds the spacecraft was transferred to internal electric power - freed from the launch pad power which had been supplied through the umbilical cables.)
The huge bird strains at its moorings as thrust power builds up. The remaining umbilical service ares are retracted, begin to swing back.

The Hold Down Arms and Tail Service masts are released...

Half a second later the soft release mechanisms give way. They consist of from 8 to 16 tapered pins attached to the launch platform and pulled reluctantly through a die attached to the vehicle as it flies the first six inches of the Apollo mission.